PROJECT SUMMARY The Chronic Kidney Disease in Children Study (CKiD) is a multi-center, prospective, observational cohort study of children aged 6 months to 16 years with mild to moderately impaired kidney function at study entry. Two clinical coordinating centers (CCCs) at the Children's Hospital of Philadelphia (CHOP), and Children's Mercy Hospital (CMH), and a data coordinating center at Johns Hopkins Bloomberg School of Public Health have formed a cooperative agreement to conduct this study. Since its inception in 2003, the scientific aims of CKiD have been to determine the risk factors for decline in kidney function and the effects of kidney function decline on the risk factors for cardiovascular disease, growth failure and its associated morbidity, neurocognitive function and behavior. The purpose of this application is to request funds to continue the cohort study from August, 2018 to July, 2023. The aims of the current proposal will expand on the original aims to include completion of recruitment of 190 children with congenital anomalies of the kidney and urinary tract and other non-glomerular kidney disorders early in the course of CKD, characterization of the impact of duration of CKD, dialysis and kidney transplantation on the cumulative burden of cardiovascular risk factors, remote assessment of physical activity and blood pressure, development of novel approaches to identify risk factors for CKD progression, enhancement of research in childhood CKD through collaboration with other cohorts, and continued provision of a broad data resource for the scientific community. The Principal Investigator of the Midwest Clinical Coordinating Center at CMH has clinical expertise in kidney disease in children, clinical research design, recruitment and retention, quality control of study procedures, and organization of collaboration across the multiple participating sites in CKiD. The CKiD study encompassess a geographically and racially diverse cohort. The structure of CKiD and its support of ancillary studies continues to stimulate the generation of new knowledge pertaining to the progression of CKD and the development and evolution of associated co-morbidities, as well as the publication of those data. The infrastructure of CKiD continues to serve as a platform for career development awards for junior investigators, and ancillary R01s for more senior colleagues. Most importantly, with longer follow-up and additional recruitment of subjects early in the course of CKD, we will contiune to characterize novel biomarkers of kidney inury that are associated with CKD progression and its sequellae to help inform future therapeutic trials.